Bulletin No. 261 Seriesl £< ^noimc Ge0 ]°l{' ''' „ 
\ E, Chemistry and Physics, 4o 
DEPARTMENT OF THE INTERIOR 
UNITED STATES GEOLOGICAL SURVEY 
CHARLES 1). WALCOTT, DIRECTOR 
PRELIMINARY REPORT 
ON THE OPERATIONS OF THE 
COAL-TESTING PLANT 
UNITED STATES GEOLOGICAL SURVEY 
AT THE 
LOUISIANA PURCHASE EXPOSITION, ST. LOUIS, MO., L904 
EDWARD W. PARKER, JOSEPH A. HOLMES, MARIUS R. CAMPBELL 
Committee in Charge 
WASHINGTON 
GOVERNMENT PRINTING O F F I C E 
1905 
